Theory of Lattice Raman Scattering in Insulators

Excitonic effects on the two-color coherent control of interband transitions in bulk semiconductors

“…The part of the Coulomb partial wave phase shift δ l (κ) that does not depend on r is arg (Γ (l + 1 + i/(a cv κ))) 72,82 ; when inserted into (60), this reproduces (45). In contrast, the allowed-allowed two-photon pathway reaches an s wave and thus there is no phase shift for population control or spin control.…”

“…67,68 It has been used to study excitonic effects on one-photon absorption, 36 two-photon absorption, 38 and other nonlinear optical processes. 44,45,46,47,48,49,50 We subsequently describe a generalization that accounts for degeneracy and multiple bands.…”

“…where the intrinsic phase is given by (45), and The Coulomb enhancement factor F (I) a-f (ω) is plotted in Fig. 3 with the approximation that N (a-f) ccvv = 1 (see Appendix A).…”

“…where F (I) a-f is given by (47), δ is given by (45), and µ (I-free) is the spin current injection pseudotensor in the independent particle approximation. Under similar approximations, the spin control pseudotensor is…”

“…These excitonic effects have long been understood qualitatively on the basis of a simple two-band model in the effective mass approximation, 36 which is even quantitatively accurate for typical semiconductors. 34 Excitonic effects on nonlinear optical properties of bulk semiconductors have also been studied in the effective mass, Wannier exciton approximation 37,38,39,40,41,42,43,44,45,46,47,48,49,50 and only recently with ab initio methods. 51 The two-photon absorption spectrum shows a different set of exciton lines and a Coulomb enhancement that is weaker than its one-photon counterpart.…”